<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>登录页面</title>
    <!--引入样式-->
    <link rel="stylesheet" href="css/common.css">
    <link rel="stylesheet" href="css/login.css">
</head>
<body>
    <!-- 导航栏-->
    <div class="nav">
        网页聊天
    </div>
<!-- 主窗口区-->
    <div class="login-container">
        <div class="login-dialog">
            <h3>登录</h3>
            <div class="row">
                <span>用户名</span>
                <input type="text" id="username">
            </div>
            <div class="row">
                <span>密码</span>
                <input type="password" id="password">
            </div>
            <div class="row">
                <button id="submit">登录</button>
            </div>
        </div>
    </div>

    <!--引入<jquery-->
    <script src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
    <!--实现前后端交互的逻辑-->
    <script>
        let submitButton = document.querySelector('#submit');//选择到登录按钮
        //点击后执行
        submitButton.onclick = function(){
            //1.先获取到输入框中的内容
            let username = document.querySelector('#username').value;
            let password = document.querySelector('#password').value;
            if(username == '' || password == ''){
                alert("当前输入的用户名或者密码为空！");
                return;
            }  

            //2.再发送ajax请求进行登录
            $.ajax({
                url: '/login',
                type: 'post',
                data: {
                    //如果直接拿个对象传给这个ajax方法的data属性，ajax就会默认按照form表单的格式来构造数据，username=zhangsan&password=123
                    username:username,
                    password:password
                },
                //3.处理响应
                success: function(body){//此处的body相当于响应的user对象
                    if(body && body.userId > 0){
                        //登录成功
                        alert("登录成功！");
                        //跳转到客户端主页面（聊天页面）
                        location.assign('/client.html');
                    }else{
                        alert("登录失败！");
                    }
                }
            });
        }

    </script>
</body>
</html>